At the risk of being told where to stick my ;!?"s, I'd like to make a case for punctuation, and apostrophes in particular. The whole point of punctuation is to avoid ambiguity. Most apostrophes are used to show a contraction where letters have been left out of a word or two words are joined, or to indicate possession. 'I'd' is a contraction of 'I would'. 
"That's obvious," I hear someone say, but without the apostrophe, it would read 'id', which is a pyschological term referring to the instinctive and impulsive part of an individual. Maybe my id makes me want to defend apostrophes. 
Apostrophes are often essential to differentiate between plurals and possessives. Sadly, they're all too often put in the wrong place, especially when used with numerals. Plurals don't require apostrophes, possessives do. When you see 'over 18's only' meaning people (which is plural) aged over 18, the apostrophe is wrong. As it's written, it means something belonging to someone or something called 'over 18'. Try writing the figure out. You wouldn't write 'over eighteen's only', would you? There's a similar problem with '60's music'. Could this mean music belonging to the decade? No. Write the figure in full. Music belonging to the sixties would be 'sixties' music', therefore in figures it should be 60s'. If the aim is to describe the music, then sixties is an adjective and no apostrophe is required i.e. 60s. The example seen all too often, '60's', can only be correct if it refers to music belonging to 60 i.e. 'sixty's music'. Got that? Good.
There is only one instance where I've found a misplaced apostrophe useful. That was in a town I was unfamiliar with, in a sign on the side of a building near where I'd parked the car. I would never have found where I'd left it, if I hadn't been irritated by that sign.